Apparatus for making gears



H'. N. ANDERSON.

APPARATUS FOR MAKING GEARS.

APPLICATION FILED DEC-18,1917.

1,377,175. Patented May 10,1921.

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APPARATUS FOR MAKING GEARS.

APPLICATION FILED DEC 18 I917- Patented May 10, 1921.

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ANDERsomor CLEVEIlAND, onto, AssIeNon 'ro THE ANDERSON COMPANY, or CLEVELAND, 01110, A coRroaA'rIoN or 0310.

PATENTS Arrmmrus ron MAKING emas.

Specification of Letters Patent.

Application filed December 18, 1917. Serial No. 207,650.

- To all whom it may concern:

Be it known that I, HAROLD N. ANDERSON,

a citizen of the United States, residing at Cleveland, Cuyahoga county, Ohio, have invented certain new and useful Improvements in Apparatus for Making Gears, of which the following is a full, clear, and exact description.

My invention relates to shrouded ears composed of forged metalas distinguished from cast metal. Shrouded gears are well known in the mechanical art and are extensively used in certain classes of machincry, because of their great stren h. Their' use has heretofore been restricte however,

because of there being no way to make them, other than to cast them. Inasmuch as cast gears cannot be made very accurate, nor can their surfaces be made smooth and uniform, the use of shrouded gears has practically been limited to what is ordinarily classed as rough machinery.

' In my several United States patents, among which are Nos. 1,001,799; 1,240,913; 1,240,914; 1,240,915; 1,240,916; 1,240,917 and 1,240,918, I have disclosed various machines for "making gears by rolling a tootheddie against a heated blank. By this means I have made spur and bevel gears; also herring bone gears. My present invention is a method. of making shrouded gears by the.

rolling process. As a result of; the rolling the metal in the teeth is very compact an free from flaws; it is in fact what is known as mechanically refined. This mechanical refinement removes most of the blow holes and other imperfections, and those which are not removed are flattened and orientated in such away as to be rendered'inocuous.

The metal is also hardened to a-greater or less extent by the action of the die, and its wearing qualities very much improved. Be-

cause of thehea'ted condition of the blank at the time the teeth are being formed the finishedgear is practically free from internal stresses which would tend to distort it if subjected to heat treatment.

In the accompanying drawings,

Figurel is a face view of a shrouded spur gear, partly in section.

Fig. 2 is a side view of a fragment of a shrouded spur gear.

Patented May 10, 1921.

F 3 is a side view of a shrouded bevel holder for cation resembling the modification shown in;

8 shows a fragment of a die, illustratmg the beveling of the teeth to facilitate its wlthdrawal from the blank.

Fig. 9 shows a fra ment of a gear, illus-- trating the effect on t die teeth.

Fig. 10 is a gear rolling machine.

The operation of rolling gears is briefly this: A heated blank is inserted in a rotae gear of beveling the table support or holder, and the holder r0- tated. A rotating toothed roll is then pressed against the heated blank, the holder and roll being gradually brought closer together, causingthe teeth of the toothed roll or die to sinkinto the metal of the blank and form teeth conjugate to its own teeth. The original diameter of the blank may be about equal to the pitch-diameter of the gear about equaling the metal necessary to form to be made from. 1t, the metal displaced by .the die to form the dedenda of the teeth the addenda. I have found that confining the metal at the sides of the tooth-receiving zone of the blank aids materially in the formation of the teeth and improves the quality of the metal of which they are composed. I at first confined the metal closely, making no provision for excess metal. This,

however, necessitates the blanks containing just the correct amount of metal, If the blank has too little metal the teeth will not be filled out. If there is too much metal, the

excess, having no lateral outlet, is carried around the blank by the die; '5. (2., it flows ahead of the die, so to speak, and inequality or other imperfections in the teeth may re sult. After long and costly experimentation I have found that a limited lateral outlet for the metal is not inimical to the process. That is, I have found that a limited space at the sides of the tooth-receiving zone of the blank, into which excess metal can flow, affords all ofthe advantages .of confinement of the metal, while entirely eliminating the difliculties which may arise from the presence of excess metal. Thus the problem of uniformity and precision in the blanks was solved, and what is more important I have discovered a new method of making shrouded gears.

In Fig. 4 is illustrated, rather diagrammatically, the preferred form of blankholder. This holder comprises the disks 20 -20 between which the blank is clamped. The disks are preferably formed complementary to the contour of the blank, so that they fully support the blank. The die-roll 21 is shown in the position it occupies at the time the rolling of the blank is completed.

The disks have extensions 22 between which the die operates, but the distance between the extensions is sufiicien-t to leave a space 23 at each side of the die. The metal of the blank may extend more or less into these spaces 7 in the beginning or it may not. This is practically immaterial, so long as. the blank con tains sufficient metal. The perimeter of the space being open, superfluous metal is permitted to flow toward the axis of the die.

The space s23 need not be as broad as they are shown in the drawings, a comparatively small space being sufiicient to allow the escape of superfluous metal. But for making shrouded gears a broader space is provided. After the gears are rolled they are mounted in a lathe to be turned. If the shrouds are not to be retained they are turned off; If

they are to be retained its periphery is turned down to orslightly below the pitch-line, the finished gear being shown in Fig. 1. It is s only necessary, of course, to turn the shrouds I -of the shaft 30,,and the'other is secured to the end of shaft 31, this shaft being movable endwise to let in the blank by means of the lever 32.. The die-roll is mounted on a shaft journaled in bearings 33-33, which is driven through universal joints by a gear 34. A-

train of gears drives shaft 30, a gear 38 on the end of shaft 30 driving gear 34. All of the mechanism so far mentioned,except the bearis connected by a link 45 and cross head 46- to the screw 47 which is mounted to slide but not rotate in bearings 48-48. By means of clutches 49 and 50, controlled by a vertical lever 51, the gear 52 may be rotated in either direction by the shaft 36. The hubof this gear is threaded to fit the screw andbeing confined between the bearings 4848 rotation of the gear moves the screw endwise in one direction or the other, according to the direction of rotation of gear 52. Move ment of the screw to the left, as seen in the drawing, brings the links of the toggle into parallelism and draws the table 40 toward the shaft 30, thereb pressing the rotating die into the blank. t its right hand end the shaft 31 carries a cam or ramp 53 which is connected to the shaft through a ball thrust chine and a more extended description may be found in my Patent No. 1,240,915, issued September 25, 1917.

In Fig. 5 I show a modification, wherein there is no perimetrical opening, the inwardly turned flanges. 6060 on the extensions 2222 approaching so close to each other as to leave just room enough for the die between them.

In Fig. 6 I show an arrangement for rolling bevel shrouded. gears. The apparatus here shown is intended to be used on a ma chine similar to the one shown in my Patent No. 1,240,916, and comprises a holder 65, mounted 'on a rotatable shaft (not shown) recessed to receive the blank. A conical block 66 is adapted to set on the blank and is provided with a dowel 67 to enter a hole in the center 'of the blank. The block is pressed against the blank and the blank thus clamped in the holder by a circular, flat faced, block 68, which is mounted on the end of a rotatable longitudinally movable plunger (not shown). The die 69 consists of a crown'gearcut on the end of a cylindrical ring, which is mounted and 'moved longitudinally by means not shown.

The die is shown in the position it occupies at the terminatlon of the tooth forming, op-

eration and it is seen that its teeth operatebetween elements which limit the lateral flow of metal just as has been described in connection with Fig. 4. That is, there are spaces 70 at the sides of the tooth receiving zone of the blank, which spaces have perimetrical openings similar to those in Fig. 4.

A'bevel gear made in this kind of a holder is I c the blank. .In dotted lines the shape of the also extend ou't farther than shown in the"- figure. The shrouds are turned down to the pitch-line and the teeth are beveled from the pitch-line outward so as to permit their entrance into the mating gear, which is supposed to have also been formed with a beveled die-roll. In order to provide clearance and allow for a little side play of the gears the addenda. of the teeth are made slightly narrower than the space they enter in the mating gear.

t is to be understood that my invention is not limited in its application to th specific embodiments illustrated. It is only limited by the scopeof the appended claims.

What I" claim is as follows:

1. In a machine for rolling gears, a holder for blanks which extends at each side of the tooth-receiving zone of the blank so that the tooth-forming die must operate between the extensions, the space between said extensions being wider than the die and having perimetrical openings through which ,excess metal may escape.

2. In a machine for rolling gears, a

holder for blanks and elements on each side portions that lie at th sides of the toothreceiving zone of the blank, but removed therefrom so. as'to provide limited spaces for metal" outside of the tooth-receiving zone; said portions that lie at thesides of the tooth-receiving zone having difi'erent proportions, whereby one is adapted to lie at the-inside and the other at the outside of said zone.

4. In a machine for rolling bevel gears, a pair of members adapted to receive between them and thereby support a bevel gear blank while teeth are being, rolled thereon, said members having extending portions that lie at the sides of the tooth-receiving zone of the blank, but removed therefrom so as to provide limited spaces for metal outside of the tooth-receiving zone; said portions that lie at th sides of the tooth-receiving zone having different proportions, whereby one is adapted to lie at the inside and the other at the outside of said zone, said elements being so formed that the space between them quite to their edges is broader than said tooth receiving zone, thereby affording an outlet for metal in excess of the capacity of said spaces.

' In a machine for rolling gears, elements between which the active teeth of the tooth-forming die and tooth-receiving zone of the blank lie while the die is operating on the blank, the space between said elements being broader than the die and having a perimetrical opening through which superfluous metal may escape.

6. In a machinefor rolling gears, a pair of members between which to clamp a blank, having extended portions between which the tooth-receiving zone of the blank lies, the distance between said extensions being broader than said zone,-thereby providing spaces for metal outside of said zone. said extensions being so formed as to afford an outlet for metal in excess of the capacity of said spaces, means for moving one of said members longitudinally to clamp the blank, means for rotating the members with the blank clamped between them; a die roll, means independent of the blank for rotating it, and means for producing relative movement of approach between the rotating die-roll and said rotating members.

7. In a machine for rolling gears, a holder for blanks which provides support for the tooth-receiving zone of the blank, to prevent recession of the metal in the direction of the die pressure; and elements stationed on each side of the tooth-receiving zone to .bein formed said elements bein se arated from said aonebyspaces which permit a lil limited lateral extension of the blank beyond the toothed zone, said elements being so formed as to afford an outlet for metal in excess of the capacity of said spaces, a tooth-forming die, and means independent of contact between the die and blank for producing relative movement between the die and blank whereby to form teeth on the blank. 1

9. In a machine for rolling bevel gears, means for supporting .a bevel gear blank while teeth are being rolled thereon, and elements at each side of the tooth receiving zone of the blank but removed therefrom so as to afford space formetal outside 15 of said zone, said elements having different forms, whereby one is adapted to serve at the side nearest to and the other at the side farthest from the axis of the blank.

In testimony whereof Iaflix my signature 20 in the presence of two subscribing witnesses.

HAROLD N. ANDERSON.

Witnesses R. W. TOUZEAU, WM. BoHLEBER. 

